This invention relates to the cooling of bus bars which connect an exciter supplying direct current (D.C.) power to the field of an electric power generator. Various exciters are used for such purpose, including brush exciters and brushless exciters with the brush exciters including carbon brushes on a collector attached to the end of the generator field. Brushless exciters include rectifier wheels and bore pack rectifier configurations. The rectifiers are assembled in the bore of the power generator field, and all of these exciters require that the bus bars carry the heavy DC current flow from the exciter to the generator field.
One configuration for bus bar connectors uses two uninsulated half round copper sections which are separated by an insulating sheet and positioned within an insulating tube. This assembly is slid into the bore of the generator field and connections are made from the ends of each bus bar to the generator field coil and exciter.
However, the heavy current flow leads to heating problems and the necessity to cool the bus bars. One method of cooling the bore bus bars utilizes a metal pipe or tube surrounding the insulated bus bars and spaced from the generator field bore by angle iron spacers welded to the outside diameter of the metal pipe or tube, such that cooling gas or air can flow in the passage between the outside of the pipe and the inside of the field bore to remove heat from the bus bars. However, the insulation and pipe are interposed between the bus bars and the cooling medium, thereby detracting from the effectiveness of the cooling.
Moreover, such arrangements add weight, size, and complexity; and an increase in the generator field bore diameter which presents a number of design problems. In addition, the clearance between the metal pipe and angle iron assembly and the generator field bore, required to enable sliding the assembly into the generator field, allows movement and noise during operation.